The purposes of this study were to investigate the rate of change with age of simple lower-limb reaction time (RT) in women and determine the relationship among RT. strength, and physical activity. Independent, community-dwelling women aged 20–89 years (N = 217) were assessed for knee-extension RT, maximal voluntary isometric contractions of the knee extensors (KE), and physical activity level. Trend analysis by ANOVA and regression analysis on RT were performed. Lower-limb RT increased and KE strength and physical activity level decreased linearly across age groups (p < .001). Active women had faster RTs than those of inactive women of the same age (p < .01). From multiple-regression analysis on RT, only 1 predictor variable. KE strength, emerged. Stronger women had faster RTs than those of weaker women (p < .0001), regardless of age and physical activity. Although RT was slower in older women, higher levels of strength and physical activity were associated with faster RTs in this group.
Hunter is with the Department of Kinesiology and Applied Physiology at the University of Colorado. Boulder, CO 80303-0354. At the lime of this study, she was with the School of Exercise and Sport Science at the University of Sydney, Australia. Thompson is with the School of Exercise and Sport Science, and Adams, the School of Physiotherapy, Faculty of Health Sciences, at the University of Sydney, Lidcombe, 1825, NSW Australia.